How to Upgrade from 3.1.2 to 3.2.0

[Rene]

Thx Shawn, but after every update I first always do a health check, that was ok. I also did a run in debug mode - Mikes (n00dles101) plugin. Must say, was getting warning ...

Warning: ini_set() has been disabled for security reasons in /.../public_html/plugins/debug.php on line 32

My first thought was this plugin has to be updated for 3.2.0 version. By default it's deactivated so I didn't pay much attention to it.
After your suggestion I just activate debug mode again, but now via config file and I'm getting next warning ...

Warning: ini_set() has been disabled for security reasons in /.../public_html/admin/inc/common.php on line 83

So after checking my folders & files permissons on /data/other/logs/ I suddenly saw some errors on 'Data File Integrity Check'

Warning: simplexml_load_string() [function.simplexml-load-string]: Entity: line 3: parser error : Extra content at the end of the document in /.../public_html/admin/inc/basic.php on line 287

Warning: simplexml_load_string() [function.simplexml-load-string]: gin> in /.../public_html/admin/inc/basic.php on line 287

Warning: simplexml_load_string() [function.simplexml-load-string]: ^ in /.../public_html/admin/inc/basic.php on line 287

Can this be related to a corrupt XML file?